Lionel Messi scored a late penalty as Barcelona shook off a post-Clasico hangover and edged to a 1-0 win over Real Sociedad at Camp Nou.
Having lost first place in their defeat to rivals Real Madrid at Santiago Bernabeu six days ago, Barca took the chance to return to the summit, albeit in an unconvincing Camp Nou victory on Saturday.
Messi came into the contest having failed to score in six of his last seven games but he converted the crucial spot-kick with nine minutes remaining after a VAR review adjudged Robin Le Normand had handled a left-wing cross.
Madrid now trail by two points but have the chance to reclaim top spot in Sunday's match against Barca head coach Quique Setien's former club Real Betis.
